基于时间Petri网的工作流模型分析

工作流管理的最终目的是实现适当的人在适当的时间执行适当的活动.企业要获得竞争力,需要在工作流模型中考虑与业务过程相关的时间约束.一个考虑时间因素的工作流模型,需要在投入运行前进行时间规范与验证,以保证工作流执行的时间协调.通过为工作流网元素扩展时间属性,得到集成业务过程时间约束的工作流模型??时间约束工作流网(TCWF-nets).基于对业务活动的可调度性分析,提出了时序一致性验证方法,确保工作流执行中活动之间时间交互的安全性.在所附加的时间约束下,该可调度分析方法不仅能够检测某一给定工作流调度的时间可行性,还能对特定的实例给出一个最优调度,使工作流执行延迟最小.研究结果表明,该方法支持业务过程的时间建模与分析,对于丰富现有工作流系统的时间管理功能以及增强现存工作流软件对动态业务环境的适应性具有重要意义.

Workflow Model Analysis Based on Time Constraint Petri Nets

The ultimate goal of workflow management is to implement the right person executes the right activity at the right time. To make enterprises more competitive, time-related restrictions of business processes should be considered in workflow models. A workflow model, which considers time related factors, requires time specification and verification before it goes into production so as to guarantee the time coordination in workflow executions. Through extending time attributes for the elements in WF-nets, this paper investigates the integration of the time constraints imposed on business processes into their workflow models and the new nets are called TCWF-nets. Based on analyzing the schedulability of business activities, a time consistency verification method is put forward to assure safe time interactions between activities during workflow executions. The schedulability analysis method can not only check for the time feasibility of its execution for a given workflow schedule when the time constraints are imposed on business processes, but also give an optimal schedule to guarantee the minimum duration of workflow execution for a specific case. Research results show that this method supports the time modeling and analysis in business processes, and has an important value in enhancing time management functionality as well as the adaptability to dynamic business environments of current WFMS.